The present invention relates to a magnetic disk inspection apparatus and more particularly, to a magnetic disk inspection apparatus which records and reproduces an inspection signal onto and from each track on a magnetic disk and inspects quality of the magnetic disk on the basis of the reproduction signal.
In magnetic disks in general (hereinafter referred to as a "disk(s)", inspection whether or not a recorded signal can be reproduced correctly is conducted and an inspection method referred to as "radial modulation measurement" is included among the inspection methods.
This inspection is made particularly for evaluating whether or not the disk can be used as a servo disk. An inspection signal is recorded in place of a servo signal onto a blank disk onto which no recording is made, this inspection signal is then reproduced and the reproduction signal is inputted to an oscilloscope.
Next, an inspector has the reproduction waveform of the reproduction signal displayed on the oscilloscope and determines the peak values of a plurality of reproduction signals for each track.
The inspector inputs the peak value to processing unit such as a personal computer so as to calculate an average value for each sector of each track. In the case of this inspection, the difference between the average values in the same sector of adjacent tracks is determined. Suitable processing is conducted on this difference and the result of the processing is compared with predetermined allowable value so as to judge quality of the disk.
In accordance with the conventional inspection method described above, however, the inspector must carry out a series of manual operations of inputting the reproduction signals to the oscilloscope, observing the reproduction waveforms to detect the peak values, etc, and inputting the peak values, etc, to the personal computer or the like for processing. Accordingly, there arise problems that an extremely long time is necessary for the inspection and the inspection itself is troublesome.